Am 08.01.2012 12:16, schrieb Avi Kivity: > On 01/07/2012 06:09 PM, Peter Maydell wrote: >> On 7 January 2012 04:40, Andreas Färber <afaer...@suse.de> wrote: >>> I noticed you're dropping a comment about tlb_flush(). Is that because >>> it was dead code, or does the Memory API take care of it for us? >>> (I assume the former because memory_region_set_enabled() does not take a >>> CPUState* to operate on.) >> >> Arranging for a tlb_flush if needed has to be the Memory API's >> problem, because everything that uses the memory API to rearrange >> the view of the address space has exactly the same requirement that >> anything else in QEMU has to be told it may need to redo any caching >> data structure it has set up. In particular, this doesn't apply just >> for a single CPUState* -- in a multicore system every CPU has to be >> made aware that the world has changed, not just the one which >> happened to do the store to the "remap the flash" register. >> Also the memory API is the only thing that knows whether the region >> was already enabled (ie this is a no-op), whether some other region >> is overlapping so in fact it makes no difference whether we enable >> or disable this one, etc etc). >> >> So basically I dropped that line because it was a bit of commented >> out code with a ??? marker appended, and the device layer is the >> wrong place to be trying to solve the issue it was gesturing at. >> > > Correct, and the memory core will flush the tlb, so all is well.
Hm, I had grep'ed for tlb_flush in memory.* without a hit... I would've assumed to find tlb_flush_all() somewhere. Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
